Firstly, nice images. Ideally you need to shoot at the "blue hour" - at twilight - to create images with impact. Or remove the sky as it does not lend much if too dark.

Remove the sky??

I hate the idea that I can only take photos for one hour of the day. I want to be able move around at night, find beauty, and capture it.

Unfortunately, for shots like your first (which I like by the way), that's the best answer. You want the natural light and artificial light to be balanced a little better so you can tune your exposure to prevent blowing the highlights, keep a little color in the sky and keep some detail in the buildings. Timing is the best way to accomplish that. Doesn't mean you can't snap some skyline photos at other times, but the best of them will most likely happen when the light is just right.